No. The energy output is constrained by the decay rate of C14. Increasing the amount in use would help somewhat, but it's still many orders of magnitude away from being useful.
(The description of a few microwatts as being "less than a typical AA battery" is a massive understatement. Even a cheap AA-sized carbon cell can deliver a milliwatt -- a thousand microwatts! -- continuously for a few months.)
It varies from model to model, but with a few search in Google I got that a smartphone use approximately 5 watts, that's 5000000 microwatts. Let's assume that "a few" in the quoted text means 5, so you need 1000000 of these batteries to power a smartphone.
Each battery weight like 1 gram, so the total weight would be 1000Kg = 1 metric ton = 2000 pounds = 1 small car.
I assumes that more research can make or more usable in the consumer market?